pyvisa.errors.VisaIOError: VI_ERROR_TMO (-1073807339): Timeout expired before operation completed.

[jorsalas123]

Instrument details

• Model: Keysight E3634A
• Communication: Serial - USB

Output of pyvisa-info

root@PCBINT:/usr/local/lib/python2.7/dist-packages# pyvisa-info
Machine Details:
Platform ID: Linux-5.15.0-79-generic-x86_64-with-Ubuntu-20.04-focal
Processor: x86_64

Python:
Implementation: CPython
Executable: /usr/bin/python2
Version: 2.7.18
Compiler: GCC 9.4.0
Bits: 64bit
Build: Jul 1 2022 12:27:04 (#default)
Unicode: UCS4

PyVISA Version: 1.10.1

Backends:
ni:
Version: 1.10.1 (bundled with PyVISA)
Binary library: Not found
py:
Version: 0.4.1
ASRL INSTR: Available via PySerial (3.5)
TCPIP INSTR: Available
USB RAW:
Please install PyUSB to use this resource type.
No module named usb
USB INSTR:
Please install PyUSB to use this resource type.
No module named usb
GPIB INSTR:
Please install linux-gpib (Linux) or gpib-ctypes (Windows, Linux) to use this resource type. Note that installing gpib-ctypes will give you access to a broader range of funcionality.
No module named gpib
TCPIP SOCKET: Available

[jorsalas123]

Im tried to connect with the PSU E3634A but not receive any answer

root@PCBINT:/usr/local/lib/python2.7/dist-packages# sudo python
Python 2.7.18 (default, Jul 1 2022, 12:27:04)
[GCC 9.4.0] on linux2
Type "help", "copyright", "credits" or "license" for more information.

import visa; rm = visa.ResourceManager("@py"); inst = rm.open_resource('ASRL/dev/ttyUSB0::INSTR');
inst.query("*IDN?")
Traceback (most recent call last):
File "", line 1, in
File "pyvisa/resources/messagebased.py", line 613, in query
return self.read()
File "pyvisa/resources/messagebased.py", line 427, in read
message = self._read_raw().decode(enco)
File "pyvisa/resources/messagebased.py", line 400, in _read_raw
chunk, status = self.visalib.read(self.session, size)
File "pyvisa-py/highlevel.py", line 403, in read
raise errors.VisaIOError(ret[1])
pyvisa.errors.VisaIOError: VI_ERROR_TMO (-1073807339): Timeout expired before operation completed.

[arr-ee]

First off, you’re using a very old version of pyvisa on an old and unsupported version of python.

Next, have you checked if the instrument shows up when you list instruments? You’re running from root so device permissions shouldn’t be a problem.

[jorsalas123]

Yes, this is the list_resource

import visa
rm = visa.ResourceManager("@py")
rm.list_resources()
(u'ASRL/dev/ttyUSB0::INSTR',)

[arr-ee]

I’d suggest switching to a modern version of python & pyvisa, and trying again with pyvisa.log_to_console() for additional information.

[jorsalas123]

Gimme some minutes to install python3 and add the pkgs

[jorsalas123]

Now i tried with python3

import pyvisa
pyvisa.log_to_screen()
rm = pyvisa.ResourceManager('@py')
2023-08-21 15:54:49,093 - pyvisa - DEBUG - Reusing ResourceManager with session 3102002
2023-08-21 15:54:49,093 - pyvisa - DEBUG - Reusing ResourceManager with session 3102002
rm.list_resources()
('ASRL/dev/ttyUSB0::INSTR',)
my_instrument = rm.open_resource('ASRL/dev/ttyUSB0::INSTR')
2023-08-21 15:54:52,772 - pyvisa - DEBUG - ASRL/dev/ttyUSB0::INSTR - opening ...
2023-08-21 15:54:52,772 - pyvisa - DEBUG - ASRL/dev/ttyUSB0::INSTR - opening ...
2023-08-21 15:54:52,773 - pyvisa - DEBUG - ASRL/dev/ttyUSB0::INSTR - is open with session 8642907
2023-08-21 15:54:52,773 - pyvisa - DEBUG - ASRL/dev/ttyUSB0::INSTR - is open with session 8642907
print(my_instrument.query("*IDN?"))
2023-08-21 15:54:52,773 - pyvisa - DEBUG - Serial.write b'*IDN?\r\n'
2023-08-21 15:54:52,773 - pyvisa - DEBUG - Serial.write b'*IDN?\r\n'
2023-08-21 15:54:52,773 - pyvisa - DEBUG - ASRL/dev/ttyUSB0::INSTR - reading 20480 bytes (last status <StatusCode.success_max_count_read: 1073676294>)
2023-08-21 15:54:52,773 - pyvisa - DEBUG - ASRL/dev/ttyUSB0::INSTR - reading 20480 bytes (last status <StatusCode.success_max_count_read: 1073676294>)
2023-08-21 15:54:54,775 - pyvisa - DEBUG - ASRL/dev/ttyUSB0::INSTR - exception while reading: VI_ERROR_TMO (-1073807339): Timeout expired before operation completed.
Buffer content: bytearray(b'')
2023-08-21 15:54:54,775 - pyvisa - DEBUG - ASRL/dev/ttyUSB0::INSTR - exception while reading: VI_ERROR_TMO (-1073807339): Timeout expired before operation completed.
Buffer content: bytearray(b'')
2023-08-21 15:54:54,776 - pyvisa - DEBUG - ASRL/dev/ttyUSB0::INSTR - closing
2023-08-21 15:54:54,776 - pyvisa - DEBUG - ASRL/dev/ttyUSB0::INSTR - closing
2023-08-21 15:54:54,776 - pyvisa - DEBUG - ASRL/dev/ttyUSB0::INSTR - is closed
2023-08-21 15:54:54,776 - pyvisa - DEBUG - ASRL/dev/ttyUSB0::INSTR - is closed
Traceback (most recent call last):
File "", line 1, in
File "/usr/local/lib/python3.8/dist-packages/pyvisa/resources/messagebased.py", line 648, in query
return self.read()
File "/usr/local/lib/python3.8/dist-packages/pyvisa/resources/messagebased.py", line 486, in read
message = self._read_raw().decode(enco)
File "/usr/local/lib/python3.8/dist-packages/pyvisa/resources/messagebased.py", line 442, in _read_raw
chunk, status = self.visalib.read(self.session, size)
File "/usr/local/lib/python3.8/dist-packages/pyvisa_py/highlevel.py", line 519, in read
return data, self.handle_return_value(session, status_code)
File "/usr/local/lib/python3.8/dist-packages/pyvisa/highlevel.py", line 251, in handle_return_value
raise errors.VisaIOError(rv)
pyvisa.errors.VisaIOError: VI_ERROR_TMO (-1073807339): Timeout expired before operation completed.

root@PCBINT:/usr# pyvisa-info
/usr/local/lib/python3.8/dist-packages/gpib_ctypes/gpib/gpib.py:54: UserWarning: GPIB library not found. Please manually load it using _load_lib(filename). All GPIB functions will raise OSError until the library is manually loaded.
warnings.warn(message)
Machine Details:
Platform ID: Linux-5.15.0-79-generic-x86_64-with-glibc2.29
Processor: x86_64

Python:
Implementation: CPython
Executable: /usr/bin/python3
Version: 3.8.10
Compiler: GCC 9.4.0
Bits: 64bit
Build: May 26 2023 14:05:08 (#default)
Unicode: UCS4

PyVISA Version: 1.13.0

Backends:
ivi:
Version: 1.13.0 (bundled with PyVISA)
Binary library: Not found
py:
Version: 0.7.0
ASRL INSTR: Available via PySerial (3.5)
USB INSTR: Available via PyUSB (1.2.1). Backend: libusb1
USB RAW: Available via PyUSB (1.2.1). Backend: libusb1
TCPIP INSTR: Available
Resource discovery:
- VXI-11: ok
- hislip: ok
VICP INSTR: Available
TCPIP SOCKET: Available
GPIB INSTR:
gpib_ctypes is installed but could not locate the gpib library.
Please manually load it using:
gpib_ctypes.gpib.gpib._load_lib(filename)
before importing pyvisa.
GPIB INTFC:
gpib_ctypes is installed but could not locate the gpib library.
Please manually load it using:
gpib_ctypes.gpib.gpib._load_lib(filename)
before importing pyvisa.

root@PCBINT:/usr#

[MatthieuDartiailh]

First, I suggest you confirm the serial configuration you use (baud rate, parity and data bits) from the manual the defaults should match pyvisa defaults but it is better to check. Second, the manual state on page 131:

It is very important that you send the SYST:REM command to place the power
supply in the remote mode. Sending or receiving data over the RS-232 interface
when not configured for remote operation can cause unpredictable results

Does sending this command first or manually setting the device in remote mode helps ?

[jorsalas123]

I already config the PSU to use in remote mode
baudrate 9600
8 databit
None parity

https://www.keysight.com/us/en/assets/9018-01164/user-manuals/9018-01164.pdf?success=true
PAGE 131